Brynjulf Ottar

Control and fate of atmospheric trace metals.

I Presentations.- Natural Versus Anthropogenic Emissions of Trace Metals to the Atmosphere.- Technological Parameters Affecting Atmospheric Emissions if Trace Elements from Major Anthropogenic Sources.- Control of Heavy Metal Emissions from Waste Incinerators.- A Tiered-Profile Approach to a Global Trace Metal Emission Inventory.- Modelling the Atmospheric Transport of Trace Metals from Europe to the North Sea and the Baltic Sea.- Elemental Source-Receptor Techniques for Precipitation and Aerosol: Recent Experiences from Narragansett, Rhode Island.- On the Spatial Representativeness of Trace Element Ratios.- Statistical Methods to Apportion Heavy Metals.- Dry Deposition of Trace Elements.- Wet Deposition of Heavy Metals.- Behavior of Cd, Mn, and Pb in Forest - Canopy Throughfall.- Analytical Techniques for Atmospheric Trace Elements.- Cycling of Mercury in the Environment with Enphasis on the Importance of the Element in Acid Rain Studies.- Atmospheric Transformations of Trace Metals: Evidence for Aerosol Sulfur Association with Metals from Soil Minerals in Eastern North America and the Potential for Solubilization of Aluminium and Iron Before Deposition from the Atmosphere.- Biomonitors of Air Pollution by Heavy Metals.- II Working Group Summaries.- Technology Related to Sources of Heavy Metals and the Abatement Thereof.- Modelling Trace Element Transport.- Research Needs in Understanding Processes of Transformation, and Dry and Wet Deposition of Atmospheric Metals.- Special Topics Concerning Interactions of Heavy Metals with the Environment.

The transfer of airborne pollutants to the Arctic region

Abstract Chemical analysis of the Arctic aerosol has shown that considerable amounts of air pollutants are brought into the Arctic region in winter, particularly from sources in Europe and the eastern U.S.S.R. It is pointed out that mercury and chlorinated hydrocarbons, which after initial deposition can be re-emitted to the atmosphere by sublimation, must be subject to a systematic long term transfer from warmer to colder regions. For mercury natural emission may have resulted in an equilibrium between amounts deposited on the earth surface and ambient air concentrations. The heavier chlorinated hydrocarbons have probably not yet reached this stage. Continued large scale use of DDT and other chlorinated hydrocarbons may therefore lead to a long term increase of environmental concentrations, also in countries where restrictions on the use of these substances have led to a reduction of their concentrations in food and other biological materials. The Arctic is also the place where the first signs of a climatic change due to the increasing content of carbon dioxide and other pollutants in the atmosphere, may be detected. In order not to misinterpret any such symptoms, a detailed knowledge of the composition of the Arctic aerosol and its possible influence on the radiation balance is essential, and in view of the future oil exploitation activities in this region, the necessary investigations should not be delayed for too long.

Transport and chemical composition of the summer aerosol in the Norwegian Arctic

Abstract The chemical composition and transfer routes of the Arctic aerosol during summer have been studied at Ny-Alesund, Bjornoya, Hopen and Jan Mayen in the period August/September 1983. Samples were also collected on mainland Norway to assess the origin of aerosols transported to the Norwegian Arctic. The concentrations of Si, Al, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Pb, Zn and Cu were measured in samples from a six-stage cascade impactor of Battelle design by particle-induced X-ray emissions (PIXE). The concentrations of Cd, Ni, Pb and Zn were also measured in samples from high-volume samplers by atomic absorption spectrophotometry (AAS). Three interesting periods were identified from the element concentrations. At the beginning of the measurement campaign, the air pollutants measured at Ny-Alesund and Hopen most likely originated in northern America and Greenland. A few days later, very high concentrations of Cd and Zn at Ny-Alesund seemed to be due to air mass transfer from the Soviet Union. During the last episode, observed at Ny-Alesund and Hopen in September, elevated concentrations of several anthropogenic pollutants appeared to be due to emissions in Europe. The results show that anthropogenic emissions from sources in western Europe, Eurasia and northern America may pollute the Arctic air not only in winter but in summer as well. Present levels of air pollutants in the Norwegian Arctic in summer are within the range of levels observed in other remote regions, but are one order of magnitude higher than in Antarctica.

An assessment of the OECD study on long range transport of air pollutants (LRTAP)

Abstract Based on a survey of the sulphur emission in Europe and measurements at about 70 ground stations and by aircraft, atmospheric dispersion models have been used to evaluate the long range transfer of sulphur pollutants in Europe. The annual mean sulphur dioxide concentrations range from ~ 20 μg m −3 in rural areas close to the major source regions to ~2 μg m −3 in remote areas of the northern and western Europe. The annual mean aerosol sulphate concentrations are lower, ~10 μg m −3 and fall off more gently to ~0.5 μg m −3 in remote areas. The pattern of wet deposition shows enhanced values in areas exposed to polluted air masses and locally increased precipitation. Qualitatively the main features of the concentration fields are reproduced by the model calculations, but full quantitative agreement cannot be expected because of the many approximations made. However, on an annual basis, a correlation coefficient of 0.9 was obtained between observed and calculated values. Estimates of the annual transfer of pollutants from one country to other countries are given for 1974. These amounts are, however, dependent on variations in the annual weather pattern. Future plans for monitoring and evaluation of the long range transport of air pollutants in Europe are outlined. Experience indicates that considerable improvements could probably be obtained by introducing more detailed formulations of the chemical reactions and deposition processes in the atmospheric dispersion models.

Long-range transport of trace elements to Ny Ålesund, Spitsbergen

Abstract Atmospheric concentrations of ten trace elements (i.e. As, Cd, Cr, Mn, Ni, Pb, Sb, Se, V and Zn) were measured at Ny Alesund, Spitsbergen, during March–April 1983, and compared with those calculated using a simple receptor-oriented Lagrangian transport model and estimated emissions of the elements from various source regions inside the U.S.S.R. Very good agreement between the measured and calculated concentrations was obtained for Sb, suggesting that its emissions are accurately assessed. Fair agreement was observed for cadmium and manganese, but the atmospheric concentrations of the other elements are not fully accounted for. The major reasons for the differences between measurements and estimates are the following: incomplete emission inventory, improperly assumed dry deposition velocities, disregard of wet deposition processes, improperly assumed local deposition values, inaccuracies in the analytical procedures, uncertainties in mixing depth, and inaccuracies in trajectory calculations. In future work, seasonal variations between winter and summer concentrations should be investigated, as the differences in meteorological conditions will affect the long-range transport of pollutants.

Arctic air pollution: A Norwegian perspective

Abstract The paper gives a survey of the results obtained during a research programme in the Norwegian Arctic, financed by British Petroleum Ltd. during the period 1981–1986 under an agreement between the Norwegian Government and the oil companies. The programme included extensive measurement programmes by aircraft and at ground stations, as well as modelling of the transport of air pollutants to the Arctic. The results show that the Arctic plays an important role as an intermediate station in the general dispersion of air pollutants within the Northern Hemisphere. Continued measurements in the Arctic may therefore provide essential information concerning such questions as the change of climate and the global dispersion of polychlorinated hydrocarbons and other halogenated organics.

Origin of natural constituents in the Arctic aerosol

Abstract The existence of natural constituents in the Arctic aerosols in the Norwegian Arctic is explained by long-range transport (LRT) of eroded dust from the deserts in Asia and Africa during dust storms. The airborne seasalt contributes to the summer concentrations of Cl, Ca, K and S. During the wintertime, episodic transport of air pollutants from Eurasia adds to the concentrations of Ca and K. The S/Cl ratio during the summertime indicates that not only seasalt but also other sources contribute to the S concentrations of the Arctic aerosol, e.g. photooxidation of mercaptans and other biogenic compounds.

Aircraft measurements of air pollution in the norwegian arctic

Abstract Physical properties, particle size distribution and chemical composition of the Arctic aerosol aloft have been studied to assess the origin of polluted layers of the Arctic air. Four measurement campaigns were made with the NILU aircraft during the period March 1983–JuIy 1984. Evidence of very long range transport of air masses to the Arctic is presented for summer and winter conditions. These polluted air masses are observed at higher altitudes (> 1.5 km). The layers of polluted air at lower altitudes are believed to be due to episodes of air mass transport from emission areas with a temperature similar to that in the Arctic in winter, and from local sources in summer. However, further aircraft measurements are needed to support these preliminary results.

Vertical distribution of aerosols in the Norwegian Arctic

Abstract Information on scattering coefficients, size distributions and chemical composition of the Arctic aerosol, obtained from NILU aircraft measurements, has shed light on the origins of polluted air layers in the Arctic air. Very long-range, episodic transport of air masses, over several thousand kilometers, clearly affects the quality of the Arctic air, both during the Arctic summer and winter seasons. Polluted air masses, carrying a mixture of anthropogenic air pollutants from a variety of sources in different geographical areas, have been identified in the Arctic atmosphere over Svalbard at altitudes from 2.0 km to 4–5 km. The altitude of polluted air layers is higher in winter than in summer. The layers of polluted air at altitudes below 2.5 km can be traced to episodic transport of air masses from sources situated in areas with air temperatures similar to those in the Norwegian Arctic. During the BP Project aircraft measurement campaigns, the relevant sources were located exclusively in northern U.S.S.R. The long-range transport of air pollutants over northern U.S.S.R. to the Norwegian Arctic is the dominating feature in the winter half of the year, but a lesser one in the summer half. Both anthropogenic and natural pollutants from local sources may contribute to the layers of contaminated air up to altitudes of ca 1000 m, particularly during summertime.

Organization of long range transport of air pollution monitoring in Europe

In the 1950s a network of stations for observation of the chemical composition of air and precipitation was established in Europe. Analyzing these data, Oden (1968) was able to show that a central area in Europe with highly acid precipitation was expanding from year to year. This was further substantiated by Granat (1972), and the explanation is the increasing use of fossil fuels in Europe. In 1969, the problem was examined by OECD, and on the initiative of the Scandinavian countries, a joint research program to study the long range transport of air pollutants was started in 1972. The program will be completed with a final report in 1976.In this program, atmospheric dispersion models are used to describe emission, dispersion and deposition of SO2 and sulphate with particular emphasis on the acidification of the precipitation. An emission field has been constructed for Europe, and data from the European weather forecasting system are used for the dispersion calculations. Calculated concentrations and deposition are compared with data from about 70 ground stations and measurements from aircraft.Results show that the main cause for acidification of precipitation is the increasing use of fossil fuels. Large amounts of H2SO4 can be transported over distances up to a few thousand kilometers.In southern Scandinavia where the soil is highly acid (podsol), this has caused severe damage to life in rivers and lakes, and it is feared that in the future, there will be serious damage to forestry. In the Alps, where the soil has a high carbonate content, such effects are not expected. The long range transport of air pollutants has also been shown to increase the corrosion of materials.Work is now in progress to establish a more permanent system for the monitoring of air pollutants in Europe. The first plans for such a system were presented at the meeting in Oslo in December 1974, where countries from both Eastern and Western Europe participated. The work is supported by the Economic Commission for Europe, UN, in cooperation with other international organizations such as the World Meteorological Organization and the GEMS program of the United Nations Environment Programme.In this connection, studies have also been taken up in several countries concerning the effects of the long range transport of air pollutants. In the future monitoring system, a coordination of these efforts is envisaged.